3D Simulations of Planet Trapping at Disc-Cavity Boundaries

TL;DR

This paper presents the first 3D simulations demonstrating that disc-cavity boundaries act as effective traps for low-mass planets, influencing their migration and distribution in protoplanetary systems.

Contribution

It introduces the first global 3D simulation of planet migration at disc-cavity boundaries, confirming their role as robust planet traps.

Findings

Disc-cavity boundaries trap low-mass planets effectively.

Multiple trapping regions can exist at various distances from the star.

Traps may explain the observed uniform distribution of low-mass planets.

Abstract

Inward migration of low-mass planets and embryos of giant planets can be stopped at the disc-cavity boundaries due to co-orbital corotation torque. We performed the first global three-dimensional (3D) simulations of planet migration at the disc-cavity boundary, and have shown that the boundary is a robust trap for low-mass planets and embryos. A protoplanetary disc may have several such trapping regions at various distances from the star, such as at the edge of the stellar magnetosphere, the inner edge of the dead zone, the dust-sublimation radius and the snow lines. Corotation traps located at different distances from a star, and moving outward during the disc dispersal phase, may possibly explain the observed homogeneous distribution of low-mass planets with distance from their host stars.